Cells Of The Immune System Flashcards
What is the common progenitor for all immune cells?
What are the 3 initial cells formed from this progenitor?
Pluripotent haematopoietic stem cell
Myeloid stem cells
Lymphoid stem cell
Dendritic stem cells
What do myeloid stem cells differentiate into?
BLOOD CELLS AND INNATE CELLS
Megakaryocytes
-produce platelets
Reticulocytes
-become erythrocytes -> then RBC
Myeloblast
- gives rise to components on innate immune response:
- basophils
- neutrophils
- eosinophis
- mast cells
- monocytes-> macrophages (only once entered tissues)
What do lymphoid stem cells differentiate into?
NOTE: travel to thymus from bone marrow before differentiating
B lymphocytes
- mature in BM
- diff to plasma and memory cells
T lymphocytes
- mature in thymus
- diff to CD4 + CD8 + NK cells
What are the key features of the following cells:
- macrophages
- Neutrophils
- Eosinophils
- Mast cells and Basophils
1.
- recognise PAMPS
- TLR= recognise pathogen
- phagocytosis
- release cytokines
2.
- Migrate to areas of inflammation
- phagocytosis
3.
- respond to parasites
- contain granules i.e. pro-infla cytokines
4.
- Mast cells fixed in tissues
- basophils= ciruclate in blood
- cytoplasmic granules leading to release of pro-inflammatory cytokines when degranulation occurs
What are the key features of B lymphpcytes?
Mature in bone marrow
Cell surface line w/ antibodies specific to an antigen
Only recognise antigen matching antibodies
Become either plasma cells or memory cells when activated
What are the key features of T lymphocytes?
Mature from pro-thymocytes, which leave bone marrow + travel to thymus
Lined with TC receptors for specific antigen
I.e. CD4= MHC 2
I.e. CD8= MHC 1
CD4-> TH cell
CD8-> cytotoxic TC
How do cytotoxic TC destroy infected cells?
Granule exocytosis
Fas pathway activation i.e. induces apoptosis
What is the role of dendritic cells?
Take up pathogen antigen and process to present on surface via MHC 1 or MHC2
